Plastics Can Be Eaten By Enzymes And Reduce Pollution

Packs of flattened polyethylene terephthalate (or PET) bottles are carried into a depot before being pulverized as part of a recycling process at Tokyo PET Bottle Recycle Co. in Tokyo, Aug. 13, 2002. Researchers in Britain and the United States have engineered an enzyme that breaks down such plastics. VOA

Scientists in Britain and the United States say they have engineered a plastic-eating enzyme that could help in the fight against pollution.

The enzyme is able to digest polyethylene terephthalate, or PET — a form of plastic patented in the 1940s and now used in millions of tons of plastic bottles. PET plastics can persist for hundreds of years in the environment and currently pollute large areas of land and sea worldwide.

Researchers from Britain’s University of Portsmouth and the U.S. Department of Energy’s National Renewable Energy Laboratory made the discovery while examining the structure of a natural enzyme thought to have evolved in a waste-recycling center in Japan.

Finding that this enzyme was helping a bacteria to break down, or digest, PET plastic, the researchers decided to “tweak” its structure by adding some amino acids, said John McGeehan, a professor at Portsmouth who co-led the work.

This led to a serendipitous change in the enzyme’s actions — allowing its plastic-eating abilities to work faster.

“We’ve made an improved version of the enzyme better than the natural one already,” McGeehan told Reuters in an interview.

“That’s really exciting because that means that there’s potential to optimize the enzyme even further.”

The team, whose finding was published Monday in the Proceedings of the National Academy of Sciences journal, is now working on improving the enzyme further to see if it could be capable of breaking down PET plastics on an industrial scale.

Plastic pollution, Pixabay

“It’s well within the possibility that in the coming years we will see an industrially viable process to turn PET, and potentially other [plastics], back into their original building blocks so that they can be sustainably recycled,” McGeehan said.

‘Strong potential’

Independent scientists not directly involved with the research said it was exciting, but cautioned that the enzyme’s development as a potential solution for pollution was still at an early stage.

“Enzymes are non-toxic, biodegradable and can be produced in large amounts by microorganisms,” said Oliver Jones, a Melbourne University chemistry expert. “There is strong potential to use enzyme technology to help with society’s growing waste problem by breaking down some of the most commonly used plastics.”

Douglas Kell, a professor of bioanalytical science at Manchester University, said further rounds of work “should be expected to improve the enzyme yet further.”

Microplastics have been used to replace natural exfoliating materials in cosmetics and have been reported in a variety of products such as hand cleansers, soaps, toothpaste, shaving foam, bubble bath, sunscreen and shampoo. Pixabay

Everyday cosmetic and cleaning products contain huge quantities of plastic particles, which are released in the environment and could be harmful to marine life, says a new study.

Almost 100,000 tiny ‘microbeads’ – each a fraction of a millimetre in diameter – could be released in every single application of certain products, such as facial scrubs, the findings showed.

“As the study unfolded I was really shocked to see the quantity of microplastics apparent in these everyday cosmetics,” said one of the lead researchers Imogen Napper of Plymouth University in England.

The particles are incorporated as bulking agents and abrasives, and because of their small size it is expected many will not be intercepted by conventional sewage treatment, and are so released into rivers and oceans.

This could result in up to 80 tonnes of unnecessary microplastic waste entering the sea every year from use of these cosmetics in Britain alone.

Body Scrub. Pixabay

Microplastics have been used to replace natural exfoliating materials in cosmetics and have been reported in a variety of products such as hand cleansers, soaps, toothpaste, shaving foam, bubble bath, sunscreen and shampoo.

For this study, researchers chose brands of facial scrubs which listed plastics among their ingredients, and these were subjected to vacuum filtration to obtain the plastic particles.

Subsequent analysis using electron microscopy showed that each 150 ml of the products could contain between 137,000 and 2.8 million microparticles.

“Currently, there are reported to be 80 facial scrubs in the UK market which contain plastic material, however some companies have indicated they will voluntarily phase them out from their products. In the meantime, there is very little the consumer can do to prevent this source of pollution,” Napper noted.

The findings appeared in the journal Marine Pollution Bulletin. (Bollywood Country)